As just stated, the filaments are not glandular, and do not secrete.  Nor have they the power of absorption, as may be inferred from drops of a solution of carbonate of ammonia (one part to 146 of water), placed on two filaments, not producing any effect on the contents of their cells, nor causing the lobes to close, When, however, a small portion of a leaf with an attached filament was cut off and immersed in the same solution, the fluid within the basal cells became almost instantly aggregated into purplish or colourless, irregularly shaped masses of matter.  The process of aggregation gradually travelled up the filaments from cell to cell to their extremities, that is in a reverse course to what occurs in the tentacles of Drosera when their glands have been excited.  Several other filaments were cut off close to their bases, and left for 1 hr. 30 m. in a weaker solution of one part of the carbonate to 218 of water, and this caused aggregation in all the cells, commencing as before at the bases of the filaments.

Long immersion of the filaments in distilled water likewise causes aggregation.  Nor is it rare to find the contents of a few of the terminal cells in a spontaneously aggregated condition.  The aggregated [page 291] masses undergo incessant slow changes of form, uniting and again separating; and some of them apparently revolve round their own axes.  A current of colourless granular protoplasm could also be seen travelling round the walls of the cells.  This current ceases to be visible as soon as the contents are well aggregated; but it probably still continues, though no longer visible, owing to all the granules in the flowing layer having become united with the central masses.  In all these respects the filaments of Dionaea behave exactly like the tentacles of Drosera.

Notwithstanding this similarity there is one remarkable difference.  The tentacles of Drosera, after their glands have been repeatedly touched, or a particle of any kind has been placed on them, become inflected and strongly aggregated.  No such effect is produced by touching the filaments of Dionaea; I compared, after an hour or two, some which had been touched and some which had not, and others after twenty-five hours, and there was no difference in the contents of the cells.  The leaves were kept open all the time by clips; so that the filaments were not pressed against the opposite lobe.

Drops of water, or a thin broken stream, falling from a height on the filaments, did not cause the blades to close; though these filaments were afterwards proved to be highly sensitive.  No doubt, as in the case of Drosera, the plant is indifferent to the heaviest shower of rain.  Drops of a solution of a half an ounce of sugar to a fluid ounce of water were repeatedly allowed to fall from a height on the filaments, but produced no effect, unless they adhered to them.  Again, I blew many times through a fine pointed tube with my utmost force against the filaments without any effect; such blowing being received [page 292] with as much indifference as no doubt is a heavy gale of wind.  We thus see that the sensitiveness of the filaments is of a specialised nature, being related to a momentary touch rather than to prolonged pressure; and the touch must not be from fluids, such as air or water, but from some solid object.